Thimbleberry, Rubus parviflorus
By Joyce Tuharsky, WORC Member
Thimbleberries are native to western North America from California to Alaska and in some northern areas of the continental U.S. such as the cool, moist, coastal regions of the Great Lakes. In Michigan specifically, Thimbleberries are found on Isle Royal, throughout much of the upper peninsula, and in northern lower peninsula close to lakes Michigan and Huron.
There is a similar plant in northeast U.S. which the locals also call Thimbleberry, Rubus odoratus. It is almost identical but has pink flowers instead of white.
Unlike raspberries and other members of the Rubus genus, Thimbleberry bushes have no thorns! They grow as an erect, multi-branched bush, reaching up to 8 feet tall. They are perennial and deciduous—present year-round but dropping their leaves in fall. The brownish canes, 1⁄2 inch in diameter, remain over winter. This plant spreads through underground rhizomes often forming large thickets.
While most Rubus species have compound leaves, Thimbleberries are simple and palmate with 3–7 lobes, looking like maple leaves. The leaves are soft and fuzzy with irregularly serrate margins and up to 10 inches across—much larger than most Rubus species. (Psst! These soft leaves make good emergency toilet paper.)
Eric Beckers, Wildflowers.org
Thimbleberries also have relatively large flowers, up to 2 inches across. They are white (sometimes lavender) with a yellow center, five-petaled, and slightly crinkled, occurring in clusters at branch ends. The flowers and later fruits develop on 2nd-year stems.
Like Raspberries, Thimbleberries are not true berries but instead an aggregate fruit of numerous drupelets around a central core. When picked, the hollow core makes the fruit look like a thimble. These “thimbles” are about ½ inch in diaameter, ripening to a bright red or purple.
Leslie Seaton, Wikipedia Commons
Thimbleberry fruits have a unique sweet-tart flavor and are soft and velvety to the tongue. They are wonderful eaten raw or cooked in jams, pies, or muffins. However, this plant blooms and produces fruit slowly during the summer (May thru August depending on location) rather than all at once. So, it can be tough to gather enough “berries” for a recipe. But they are excellent blended with other fruits/berries. High in vitamins A and C, Thimbleberries were eaten in the past to ward off scurvy.
Butterflies, native bees, honeybees and bumble bees love Thimbleberry flowers, and native bees use this plant for nesting structure. The fruit is an important food for birds and mammals, including bears. Deer browse the young leaves and stems. This bush also hosts various species of aphids, midges and wasp larvae, some of which induce galls on the plant.
Thimbleberry shrubs can fit into an ornamental landscape better than some of its more aggressive, prickly cousins. Its white flowers are bright and cheerful. Its large leaves provide bold contrast in summer and turn bright gold in fall. This shrub prefers full sun to part shade and organically rich, moist but well-drained, slightly acidic soil.